A scanning kind electron microscope that is a kind of a charged particle beam apparatus is an apparatus that irradiates an observation sample, for example, a circuit pattern of a semiconductor wafer with an electron beam and detects emission electrons such as secondary electrons generated from the observation sample to acquire an observation image of the observation sample. In the scanning kind electron microscope, an image is generated by arranging detection signals obtained by irradiating a surface of the observation sample with a narrowed primary electron beam while two-dimensionally scanning the surface in synchronization with a scanning signal of the beam.
PTL 1 discloses a scanning electron microscope in which when scanning a range of a field of view including an observation target pattern in order to suppress shrinkage of an observation target caused by beam irradiation, an irradiation amount of a surrounding region of the observation target pattern is suppressed relative to an irradiation amount to the observation target pattern so that a beam irradiation amount over an entire field of view is suppressed.
PTL 2 discloses a panorama image synthesizing technique for dividing a region to be imaged into a plurality of regions and joining a high-resolution image acquired in each of the divided regions in order to acquire a high-resolution image over a wide range.